The 42-year-old Santa Rosa woman has been homebound and unable to work ever since her left breast was removed in September. Insurance covered the medical bills, but she's been ordered to stay off her feet -- a crippling occupational handicap for a job where she's supposed to walk, often trot, up to 10 miles a day.

Without a paycheck, Armitage has been using credit cards to buy groceries for herself and her son since the operation. Last month, she appealed to a local nonprofit agency called Sonoma County People for Economic Opportunity for rent assistance to keep her $694 a month apartment.

President Trump addresses nation after mass shooting at Florida SchoolWhite House

This was an indignity she'd never dreamed she'd have to face. But then again, she also never dreamed she'd lose all her hair.

"Most of the working class -- we're all one phone call away from devastation," said Armitage, rocking gently in a chair on her small balcony. "I've fought so hard for this" -- she gestured at the modest apartment behind her -- "and I just can't stand the thought of losing it. I've just had the carpet ripped out from under me."

Season of Sharing -- The Chronicle's holiday charity -- will help cover Armitage's living expenses through Sonoma County People for Economic Opportunity until she can go back to work. It's one less thing for her to worry about during the most stressful time of her life.

But there are thousands of other single mothers like her who don't get any help at all when life deals them an unexpected blow.

Nearly 46 percent of American single mothers live below the poverty line, according to the U.S. Census Bureau, and almost a third do not receive child support from fathers. "Single mothers are at great peril," said Madeleine Stoner, a professor of social work at the University of Southern California in Los Angeles. "They make less than men, to begin with, and they have the responsibility of caring for children. Since the early 1980s, we've seen the feminization of poverty in this country."

"Mary could be any one of us -- just one paycheck away from disaster," added Pam Vaniman, who is Armitage's caseworker at SCPEO.

But financial disaster was not necessarily the worst part of getting cancer for Armitage. Losing an intimate part of her body was much harder than she expected. "I've always been a sensual person and this is a very sensual part of me," she said. "The doctor called it a simple mastectomy, which I thought was an insulting term. There is nothing simple about losing one of your breasts."

A few days before the surgery, a customer at the coffee shop who had been through a mastectomy gave her a surprising piece of advice: "Don't forget to say goodbye to it."

At first Armitage puzzled over that but she eventually took the woman's advice. The night before surgery, she cradled the cancerous breast in her hands and cried. She now wears a foam prosthesis under her bra in its place.

Mary did her best to explain her illness to Sullivan. "Mommy's going to shave her head," she told him. He ran his fingers through her hair. "No," he said.

"He is my reason for going on," Mary said of her son. "I never intended to have him, he was unplanned, but he is my miracle. He's the most beautiful thing that ever happened to me."

The father is Armitage's former boyfriend, who lives in a nearby town. He has not been providing child support, according to Armita ge. She feeds Sullivan with the help of the federal Women, Infants and Children program, which provides vouchers to buy basic foodstuffs like milk and cereal.

Long accustomed to serving others -- that's what her job entails, after all -- Armitage is now in the unfamiliar position of needing service. It makes her uncomfortable.

"I really don't know how to ask for help," said Armitage. "All my life I've been the giver. Now, I'm finding it hard to be the receiver. I feel guilty."

Help has also been forthcoming from her friends back at the restaurant, who have offered to watch Sullivan while she goes in for chemotherapy treatments.

The outpouring of concern from her regular customers has been overwhelming, according to Bobby Flores, manager of the Lyons' Restaurant in Rohnert Park where Armitage worked.

"She's built up quite a circle of regular customers over the years and people are always asking about her," he said. "She's a very highly regarded waitress. We've been delivering get-well-soon cards to her pretty steadily."

Michael Grice, director of the nearby Spreckels Performing Arts Center, is one of those regular customers. He ordered the same thing from Mary for eight years -- two eggs over medium, bacon, English muffin with strawberry jam and coffee.

Grice ran into Armitage in public recently and could not believe how cheerful she looked.

"If anything like that happens to me, I hope I'll have her kind of strength and dignity," he said.

She has a standing offer to return to her job as soon as her health will allow. But there's no way to tell when -- or if -- that will happen. Breakaway cancer cells made it to 17 of the 37 lymph nodes in her breast, according to the biopsy. They could reappear anywhere in her body and the whole thing would start over.

Armitage is a cheerful woman by nature and she has been trying to find humor in her ordeal. She may lose her hair, but she'll soon get a fresh palette for future dye jobs, she notes with a laugh.

She has, at various times in her life, been a golden blond, a platinum blond, a redhead, a brunette and a dozen different hues in between. Her hair, now a polychromatic mix of auburn, gold and grey, will all be gone within a month.

"I'll finally get to see my natural color," she said. "I think it's dirty-blond, but I haven't seen it since I was 16."